-LRB- CNN -RRB- -- Airline passengers are already able to check in to flights , download boarding passes , select a seat on the go and keep an eye on the upgrades list thanks to recent evolutions in smartphone technology , and the options just keep growing .

A global industrywide Airline IT Trends Survey shows that more than 90 % of the airlines surveyed are increasing their investment in mobile capabilities to ease the hassles of getting through the airport and improve the in-flight experience . And the airlines are likely to find a way to generate revenue , too .

So what 's a flier to expect from airline apps on the horizon ? In the not-too-distant future , you 'll probably be able to rent a car , pay bag fees and use augmented reality to find the nearest airport bar through your airline 's smartphone app .

Delta Air Lines is putting emphasis on improving mobile functionality . While some airline apps allow travelers to make flight reservations -LRB- a feature that Delta has not introduced but promises is coming -RRB- , the world 's largest carrier is one of the few airlines that gives customers the ability to adjust travel itineraries from their mobile device .

Delayed Delta passengers who miss a connection now can immediately rebook a different flight and download a new boarding pass , all while in the air .

The airline has some new app plans up its sleeve as well . Delta declines to give a release date for the feature , but it is close to unveiling a new tool where travelers can track checked baggage from their mobile devices , according to Delta spokesman Paul Skrbec . -LRB- They can already do so on the airline 's website . -RRB-

The airline eventually could offer other services on its mobile app that are already listed on its website , such as the ability to search for hotel and car rental reservations , Skrbec said .

GuestLogix , a company that creates onboard merchandising technology , is already trying to integrate these services into an airline app with the launch of its OnTouch Mobile Concierge platform , which it pitched to major airlines this week , a company official said . The mobile app does not just offer access to itinerary details , but it also functions as a one-stop shop for airline passengers to make in-air purchases related to their trip , such as in-flight refreshments and arrangements for ground transportation , dining and entertainment in the destination city .

GuestLogix says it is in talks with most major North American carriers about implementing the OnTouch Mobile Concierge , which would likely be offered by airlines as a separate app from the ticketing-based ones that exist .

`` We are providing airlines with the opportunity to offer their passengers a streamlined experience , '' said Brett Proud , GuestLogix 's executive vice president of new markets and products . `` Disparity within the mobile channel is a huge issue despite the fact that consumers are increasingly expecting cross-platform integration and a consistent experience . The fully integrated mobile platform that we have built allows travelers to check in to flights and hotels , view travel information and updates , and receive offers from multiple airline carriers , hotels and other services -- all at one time , and in one place . ''

The hope is the OnTouch Mobile Concierge will also allow airlines to generate new revenue streams by capitalizing for the first time on destination-related purchases .

But integrating outside products and services into airline apps is not the only way that airlines hope to customize the passenger experience while increasing revenue . According to Delta 's Skrbec , the demand is likely there for airlines eventually to offer add-ons such as standby upgrades and the ability to pay for extra checked baggage through mobile applications , but industry research suggests that offering those types of mobile transactions wo n't happen overnight .

According to a report released this year by Amadeus , a company that develops technology for the travel industry , ancillary services -- from premium seating to in-flight meals -- are unlikely to be sold on airlines ' mobile platforms on a widespread level for another year or two .

So more add-ons and products will be available , but is help on the way for slogging through the airport ?

American , United and Continental airlines currently offer airport maps in their mobile apps , with Delta soon to join them . But the maps are generally useful only in locating gates ; they do n't offer detailed information on where to find food and shopping locations .

Augmented reality technology may come to the rescue here . It allows users to point the camera on their smartphone at their surroundings and receive corresponding information about their current location , such as which restaurants and stores are nearby . Amadeus 's report estimates it will take three to five years for most airlines to find a way to integrate augmented reality into an airline app .

Airlines might take some cues from a new app released by Denmark 's Copenhagen Airport this year , which became the world 's first application to use augmented reality indoors successfully -- according to SITA , the app 's developer . The app allows travelers at the airport to access not just gate information but also details on surrounding shops and services , saving them time while trying to catch a flight .

Even when it comes to selling fares through mobile clients , a service that 85 % of airlines in the Airline IT Trends Survey either offer or plan to offer by 2014 , there is room for improvement . Currently , airline apps only offer tickets with their specific carrier , and mobile customers ca n't take advantage of the flexibility offered by airline alliances .

`` Airline alliances , the Star Alliance in particular , have n't really kept pace with mobile developments , '' said Dennis Schaal , the North America editor of the travel tech site Tnooz.com . `` Granted , creating a mobile app that brings in dozens of airlines would be no easy task , but there should be some kind of booking capability at this juncture . ''

The Star Alliance has two mobile apps available for download : one that offers airport information in addition to the ability to search and track flights , and another that is a fare finder for flights on the alliance 's airlines . The Star Alliance includes airlines such as United , Continental , Air Canada and US Airways -- which does not currently offer a mobile app .

But those airlines that fail to take the full leap into the mobile world will quickly find themselves in the minority . Apps might not replace websites as the primary place where people purchase airline reservations , especially with new airline initiatives to integrate ticket-purchasing apps into social-media sites such as Facebook .

However , they 're beginning to offer a level of customer service and convenience that has never before been possible in the industry , and perhaps could even transform the experience of traveling enough to create a new barometer on which airline brands will be judged in the future .

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Airlines are increasing their investment in mobile capabilities

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Ancillary services are likely to be incorporated into the mobile menu

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Delta 's app provides the ability to adjust travel plans from mobile devices